Non-VT virtualization tools

KVM is clearly the best choice on Ubuntu for Virtualization. But this requires CPU support for Virtualization Technology (VT).

We have been operating for 2+ years on the premise that VT would be ubiquitous in the near future, enabling full virtualization everywhere.

I believe that this premise has proven false. While much (though not all) server hardware has VT, VT is a premium feature on much laptop, desktop, consumer-grade hardware.

In particular, hardware shipping from the major vendors with Ubuntu preloaded is often netbook, or low-cost hardware options that rarely have VT.

I suggest that we should reconsider our options for providing some form of supported virtualization for hardware without VT.

The options:
 * qemu
  * basic emulation, no acceleration at all, very slow
 * kqemu
  * as of Karmic, this is no longer an option; upstream qemu-kvm disables kqemu support because it breaks kvm
  * as of Lucid, the qemu-0.12 version we're planning carry will not have the kqemu code in the tree at all
 * xen
  * still requires massive patch for dom0, very difficult to support
 * virtualbox
  * extremely popular in the community
  * nice gui
  * slow compared to kvm
  * fast compared to qemu